Issue: [4.1 Beta 2] Breadcrumb item for wiki index is redundant when already viewing the index

In XenForo, the intended behaviour for breadcrumbs is to not include the current page in the breadcrumb trail. This just wasn't consistently implemented in XF's core templates pre-2.0: https://xenforo.com/community/thread...8/post-1350203

VaultWiki includes a breadcrumb list item for the wiki index page even when viewing the index page. This links back to itself and is redundant. In order to match intended XF behaviour, the wiki index breadcrumb item shouldn't be included in the trail when the index is already being viewed. When performing any index page actions (e.g. view comments, view source code) then it would make sense to retain the current breadcrumb behaviour. E.g.:

• https://www.vaultwiki.org/xf-wiki/index.php?wiki/ - Hide breadcrumb item - Home >
• https://www.vaultwiki.org/xf-wiki/in...i/&do=comments - Retain breadcrumb item - Home > Wiki XF >
• https://www.vaultwiki.org/xf-wiki/in...o=incategories - Retain breadcrumb item - Home > Wiki XF
• https://www.vaultwiki.org/xf-wiki/in...wiki/&do=watch - Retain breadcrumb item - Home > Wiki XF